Chocolate find smells like a theory

Lucy Tobin

JUST before you ripped into your Easter egg at the weekend, did you take a moment to have a good sniff of the unwrapped egg?

While just eating chocolate is enough to put most of us in a good frame of mind, latest research suggests "odour du chocolat" – just the smell of it – can improve your mood.

This happy news comes from the Human Olfaction Laboratory at Middlesex University, where Neil Martin, a reader in psychology, investigates the effects of room smells on human behaviour. In his laboratory Martin has a square box called an AromaCube, which heats up "odorants" and percolates the smell around the room.

From that box, he discovered the power of chocolate in an experiment where he filled rooms with three smells, one of chocolate, a "malodour" of machine oil, which most people find unpleasant, and a lemony, pleasant-but-alerting odour, then monitored testers' moods.

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"The aim was to compare the effects of pleasant and unpleasant ambient odours on stress, anxiety, depression and mood," Martin explains. "And whilst we're still continuing the experiment, so far it seems that the smell of chocolate really does make people less stressed and anxious, and more relaxed."

Chocoholics will also be pleased to hear about some of Martin's earlier research. "In another study we looked at the effect of chocolate on brain activity," he says. "We presented people with a range of smells, some artificial food odours and some real food odours, with both samples including chocolate." Martin used EEG (electroencephalography) technology to record his participants' brain waves as they sniffed the air, and found that in both experiments, the chocolate smell consistently led to a reduction in a particular type of brain activity called theta, which is thought to be an index of attentiveness. "Theta levels dropped significantly across both indexes when testers smelled chocolate."

The experiment also shows there is no need for chocolate snobbery. "I know connoisseurs say posh chocolate, with a higher cocoa content, is better for your health, and it might be in some ways, but when it comes to the smell of chocolate and its resultant relaxing effect, we found it was the same however much milk the bar contains," Martin says.

But some of his other scent findings provide more significant practical effects. "Scent can affect employment," he says.

One study found that a combination of perfume and formal dress worn by an applicant led interviewers to rate them as less warm, more manipulative and less appointable. And Martin has shown people perform less well on cognitive tasks and report more symptoms of ill health when smelling a "bad" smell.

As a result, Martin says people should be aware of their "olfactory environment" to control their feelings. "People can use scents to improve alertness, well-being and anxiety," he says. "For example, another study showed that women in a dentist's waiting room that had been scented with orange reported less anxiety than those in an unscented counterpart."

In another experiment Martin and his team set up PlayStations loaded with a car rally game to test the effect of a lemon smell on driving ability. Martin invited men and women to play the game on three different levels and in three different environments, one in an odourless room, one smelling of lemon, and one of machine oil.

"We found that participants were consistently able to brake more safely and appropriately in the presence of the lemon scent," Martin reports. "It's perhaps because the smell is citrusy and alerting, and suggests that dangling a lemon-smelling air freshener in the car could make you a better driver."

But as Martin's use of words like "citrusy" shows, the psychology of smells is hard to pin down because they are so tough to describe. "The problem is, science doesn't really understand smells. We have vague terms for them, and say things like "it smells like this or that", but we don't have chemical terms for most odours. I think all the answers ... will come down to chemistry one day, but we haven't yet got to that level."

One thing is certain, however. The effects of smell tend to be short-lived. "We get used to odours very quickly," Martin explains. "After a while the odour disappears because we become habituated to it."

Guardian News & Media

2 comments

That's all well and good but I'd rather eat the chocolate too! Just for the extra mood lifting benefits!!

Commenter

Loveamintslice

Location

Sydney

Date and time

April 08, 2010, 8:31AM

While roaming at a shopping centre, the aromas of say a hot chocolate have a positive effect for sure, but, eating a block of Cadbury's milk chocolate, or even a few pieces is another level. There are some times when only eating chocolate will do.